The present invention relates to vehicle seat runners.
More particularly, the invention relates to a vehicle seat runner, comprising a stationary channel section bar made of folded and cut steel sheet, said stationary bar presenting:
a web;
two side flanges extending parallel to each other, each from the web to a free end; and
two lips extending towards each other from the respective free ends of the two side flanges, and defining between them a slot for receiving at least one support member adapted to be fixed to the vehicle seat;
the stationary bar extending over a certain length between a front end and a rear end for securing to the floor of the vehicle.
Document EP-A-0 842 807 describes an example of such a runner.
Known runners of that type give full satisfaction: in particular, they are very strong and lightweight, and they are low in cost given their method of manufacture. Nevertheless, given the constant rise in mechanical performance required by standards, it can be desirable in some cases to further improve the mechanical strength of such runners, particularly in the event of the vehicle being subjected to a frontal impact.
A particular object of the present invention is to improve the mechanical strength of runners of the above-mentioned type, without excessively penalizing their weight or their cost price.
To this end, according to the invention, in a runner of the kind in question, the stationary bar is engaged in an extruded reinforcing bar made of a light alloy, the reinforcing bar being secured to the stationary bar by presenting, itself, a substantially channel section with a web placed against the web of the stationary bar, two side flanges hugging the flanges of the stationary bar, and two lips extending the flanges of said reinforcing bar and overlying the lips of the stationary bar, so as to bear against said lips of the stationary bar; and said reinforcing bar is placed at the rear end of the stationary bar and extends over a length that is shorter than one-third of the length of the stationary bar.
By means of these dispositions, the stationary bar is reinforced at its rear anchor point, which is subjected to greater tear-out forces in the event of a frontal impact accident. This provides considerably improved mechanical strength, specifically by preventing the stationary bar from opening under a violent tear-out force from the seat. In addition, the reinforcing bar is of low cost and is lightweight, and it does not interfere with normal operation of the runner.
In preferred embodiments of the invention, use can optionally be made of one or more of the following dispositions:
the reinforcing bar has an inside surface that is complementary to the stationary bar, said reinforcing bar being in contact with the stationary bar over its entire inside surface;
at least one hole is made through the web of the stationary bar towards the rear end of said stationary bar in order to receive a bolt for fixing to the floor of the vehicle, the web of the reinforcing bar also having a hole in register with the hole in the web of the stationary bar so as allow said bolt to pass;
the reinforcing bar is of a thickness greater than 5 millimeters (mm), at least over its flanges and lips;
the web of the stationary bar forms two side ledges extending towards the lips of said stationary bar and extended by the flanges of the stationary bar, while the reinforcing bar presents two thick zones placed in register with said ledges and coming into contact with the stationary bar beneath said ledges, respectively, said thick zones presenting a thickness greater than the thickness of the flanges of the reinforcing bar: these thick zones enable the strength of the reinforcing bar to be increased since said thick zones are situated in a portion of the reinforcing bar which is subjected to particularly high mechanical stresses in the event of an accident;
the thick zones of the web of the reinforcing bar have a thickness of material of not less than 10 mm;
the length of the reinforcing bar is shorter than 10 centimeters (cm);
the runner further comprises said support member in the form of a moving bar of steel slidably mounted in the stationary bar; and
the moving bar is of upside-down channel section with a web parallel to the web of the stationary bar and with two side flanges extending the web of the moving bar towards the web of the stationary bar between the side flanges of the stationary bar, the side flanges of the moving bar being extended outwardly by lips in the form of troughs engaged beneath the lips of the stationary bar, which lips of the stationary bar are in the form of upside-down troughs.